1. Institute of Nanoscience and Nanotechnology, National Center for Scientific Research “Demokritos”, 15341 Agia Paraskevi, Attica, Greece
2. Department of Physics, University of Konstanz, D-78464, Konstanz, Germany
3. Department of Chemistry, University of Crete, Laboratory of Bioinorganic Chemistry, Voutes Campus, Heraklion 70013, Crete, Greece
4. Department of Physics, Swansea University, Vivian Tower, Singleton Park, SA2 8PP, Swansea, UK
5. Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Rue de l’Industrie 17, CH-1951 Sion, Switzerland